This proposal seeks to continue and expand our studies with fluoranthene (FA) by utilizing a modification of a (32P)- postlabeling assay to detect and quantify DNA adducts in mice and human lymphoblast cell lines for eventual application as a dosimeter to monitor DNA damage in tissues from occupationally or environmentally exposed human populations. Experimental protocols for the animal and human cell studies will parallel those in use in the respective Core Laboratories in which FA has been demonstrated to be tumorigenic and mutagenic, respectively. DNA will be prepared from mouse lung, liver, thymus/spleen and leukocytes, target organs and cells for PAC in this assay, and from kidney for a non-target organ source of control DNA. Adduct formation and repair will be studied as a function of tumorigenic activity, time post-treatment, and dose levels extending downward to exposures reflecting ambient environmental levels or to the minimum level for adduct detection. Experiments with metabolically competent and incompetent human lymphoblast cell lines will be similarly performed to correlate with mutagenic activity and to examine effects of FA concentration and time post-treatment. Red blood cells and sera from the mouse experiments will also be prepared for Project C-1 investigators for protein adduct measurements. DNA from mouse tissues and leukocytes and from human cells will also be isolated for Project C-3 investigators for mutational spectra analysis. In addition to the initial experimental with FA, iterative studies will be performed for other compounds (benzo(a)pyrene, cyclopenta(c,d)pyrene, 6-nitochrysene) and an effluent extract from the combustion of pulverized coal.